1. Field of the Invention
This invention relates generally to actuators and, more particularly, to actuators used in connection with a tension cable wire for use primarily in lumbar support systems for automobile car seats. The actuator disclosed here is designed to speed and streamline assembly of actuators with Bowden cables, lumbar supports, and seat frames.
2. Related Art
It is well known in the art to use an actuator in connection with a tension cable wire to provide movement in a lumbar support device located within a seat frame. Normally, the tension cable wire used in this type of configuration is a Bowden cable. A Bowden cable consists of a wire with wire ends on each side. The wire slides axially through a wire covering, sometimes referred to as a sleeve or conduit. In order to provide tension, the wire end is normally attached to a moving part while the wire covering is attached to a stationary unit. The moving part extends the wire end away from the wire covering end, thus creating a corresponding movement of the other wire end relative to the other sleeve end. The movement is used to actuate the lumbar support device. The movement is typically under tension.
It is also known in the art to use an actuator that employs the use of a threaded screw as the moving part that separates the tension cable wire end from the tension cable wire covering. Such an actuator generally contains a nut, which is also threaded, whereby as the nut is turned, the screw moves axially through the nut. One end of such screw normally has an aperture for the placement of a tension cable wire end. Somewhere near this aperture is also a stopper. The stopper prevents the tension cable wire covering end from extending with the tension cable wire end as the screw is directed away from the stopper. Such examples of these types of inventions are disclosed in U.S. Pat. No. 5,638,722 to Klinger, U.S. Pat. No. 6,053,064 to Gowing et al., and U.S. Pat. No. 5,771,751 to Schwarzbich.
Furthermore, a two screw system has also been previously disclosed whereby each screw contains oppositely threaded sections so that when the nut is rotated, the screws move simultaneously either closer or farther away from one another depending upon the direction the nut is rotated. See U.S. application Ser. No. 10/008,896 to Robert McMillen and PCT application PCT/US02/39076 to Robert McMillen. In this type of system, the stopper is generally contained on one screw while the aperture for receiving the wire end is contained on the other screw. Such a configuration allows for the same distance of movement between the tension wire cable end and the tension wire cable covering as in the single screw configuration; however, such a result is obtained with fewer turns of the nut. This advantage allows the car seat occupant to adjust the lumbar support system to the desired level of support while exerting a lesser amount of energy to accomplish the adjustment.
All of these inventions rely on some type of actuator to provide the movement necessary to produce the required tension at the opposite end of the tension wire cable needed to actuate the lumbar support device. Actuators are generally oriented in seat frames with a tab in the housing that is asymmetrical and designed to correspond with a slot in a seat frame hole provided for the actuator, or alternatively, a mounting grommet with a similar slot. Proper orientation is required for proper alignment with lumbar support components, Bowden cable routing, and consistency with left or right side seat assembly.
Many actuator housings employ the use of key hole apertures for mounting a tension cable wire end. The key holes are slots with a wide dimension designed to receive tension cable wire ends, and the bullet typically fixed to the wire end. A narrow neck of the key hole is designed to allow insertion of a tension cable wire while holding the end bullet against axial tension.
Previous actuators with single key holes in asymmetric housings cause improper installation and assembly confusion, when used as “snap-in” components. During the assembly process, workers must spend extra time and effort to ensure that the side of the housing that possesses the key hole is lined up properly with the wire end aperture such that the tension cable wire end can be properly inserted into the wire end aperture. This results in a relatively large amount of lost time in the assembly process and also leads to improper installation and confusion in the assembly of the actuators. There is a need in the art for an actuator design that will speed and streamline the assembly process and will eliminate the improper assembly and confusion associated with the asymmetric housings.